A solar installation is described. It has a solar element and a diffractively
and/or
refractively operating optical apparatus by way of which the incident sunlight
is passed directedly perpendicularly on to the solar element. The optical apparatus
is caused to track the position of the sun by way of a tracking device.
The optical apparatus uses a light-deflecting foil having portions of different
natures with a structure having a different optical action. By virtue of the action
of the tracking device the holographic foil is moved relative to the solar element
so that different portions of the foil move into an operative position above the
solar element in succession during the tracking procedure.
